A number of companies sell odor filters for use with boating applications whereby they are advertised to reduce or eliminate odors. Companies currently selling such filters include Sealand Sanigard Granules, Sealand ECO Granules, SeaRus Sales No Stank Granules and Pellets, Big Orange Granules & Pellets, and John Crisler Mod Kit Granules.
These known recreational holding tank vent filter systems have been tested and found to be deficient for removing many types of malodorous odors. Activated charcoal, generally used for this purpose, can vary in performance depending on particle size, impregnation, and concentration with air, humidity and temperature. Standard activated charcoal will often require specific treatment—impregnation, in order to attain a satisfactory degree of efficiency with regard to the removal of various types of pungent odors. However, prior art vent filter manufacturers have apparently not recognized this need.
Many irritants can contribute to pungent odors, e.g. Hydrogen Sulfide, Ammonia and Trimethylamine. These extreme odors are not normally removed by untreated activated charcoal. In fact the Journal of Health Science 47(5) 483-490(2001) reports that Standard 4×1 OR Carbon media is not good at removing Trimethylamine, Ammonia, and only marginal at removing Hydrogen Sulfide.
Current filter types are predominately single or 2-stage filter designs that are insufficient for the task at hand. Current manufacturers appear to have approached the problem from an entirely errant tact, marginally approaching vapor phase adsorption or treating an odor situation as if it were merely a water vapor adsorption issue (using non-impregnated or regular activated charcoal processed for purification of water as in a fish tank). As best the applicant can tell, untreated activated charcoal in granular and/or pellet form has been used by the prior art constructions in either a single stage homogenous supply of untreated activated charcoal in granular form or in a two stage filter with a first stage having a homogenous supply of untreated activated charcoal in granular form and a second stage having a homogenous supply of untreated activated charcoal in pellet form.
None of the prior art constructions appear to adequately address removal of gas vapor through adsorption, but instead appear to focus on removal of malodorous odors as if they were water vapor. Accordingly there is a need for new odor filters and technology in the marketplace.
There is a need for an improved filter for removing odors, particularly odors eliminating from the combination of human waste (feces and urine) which may be stored in a variety of locations, such as but not limited to septic tanks, holding tanks in boats or recreational vehicles, etc.